Control for discharge illumination



Sept, 12, 1933. R. E. BARCLAY 1,926,433

CONTROL FOR DISCHARGE I LLUMINATION Filed April 20, 1951 Patented Sept.12,' 1933 PATENT cre ice CONTROL FOB- DISCHARGE ILLUMINATION I Robert E.Barclay, Chicago, 111., assignor to Federal Electric Company, Chicago,IIL, a'corporatlon 01 New York 51 Application April 20, 1331.. SerialNo. 531,383

20 Claims,

My invention relates in general to the art oi illumination and. has moreparticular reference to illumination produced by electrical dischargesin an ionized field, of which perhaps the best known embodiment is therecently popularized. neon tube: A neon tube consists of a glass tubing,sealed, air evacuated and filled with neon gas and cro viciecl withspaced. electrodes so that by applying high electrical potential betweenthe spaced, electrodes an electrical discharge is created between theelectrodes. 'I'hiS discharge produces. various colors accordance withthe gas contained in the tube. the case of a neon gas-filled tube, thedischarge creates a brilliant red colored light. It the be containsmercury vapor, the light produced has a characteristic blue color.

Discharge i lummation. lends itself particular the creation ofarchitectural effects, for ou er." and, on account or t colors which canbe produced an oi creating combinations primary :luce modified orsecondary shades tubes oi different colors, disch ge lerl color organ."effects, t

c ion of effects i lereiu colchange and shirt 1 cm on color another inorcler to "orctluce syn litlcscopic color Tout I01 the fl-l has Zceen nooornincrcia controlling the l p e ence-cl by the electrua rliccliilficulty et with .ula'te ti ty the iiluby the discharge. as far are,no adequate method of slimming yet been suggested although a practicalway of regulating intensity oi the illumination would atly enhance thegeneral utility of the syst as a whole and woulcl make possible theminescent element or tube by absorbing a variable amount of the totalenergy supplied to the charge elerne .ation the reactive characteri ticsor tube circuits without affecting the electrical pc- 'ten'tials appliedbetween the spaced electrodes oi the tube suficieutly to impair theoperation of the luminescent element whereby'to operate same at reducedintensity with the same uniformity as at maximum intensity, it beingunderstood oi course that when the voltage, at which the tube normallyoperates, is reduced the discharge is intermittently destroyed becausethe voltage is not quite sufilcient to sustain same uniformity. "thisintermittent disconnection and recreation the discharge is commonlyreferred to as flickering anti spoils the effect of the luminiscentelement, A further important object of my invention is to provide amethod for dimming an electrical clischarg illiuninating element withoutcausing the clerics to flicker, or otl'ierwise operate inc properly.

. lmotlier irnccrtaut object oi my invention is to provide for varyingthe intensity oi in rliviriual rcerchers oi associated group ofillswhereby to create a color or impor nt object of my invention. is top cluce shale, inexpensive means (iiin I taut object resides province: eensity of an electrical v thout impairing its ich method involves thevarithe characte objects aclvantages of the ear the same is morefollowing dGSCZifQtlQ. which 1th the accom'oan ing orelerrecl emlcociment oi the The sngle illustrates an electric temincl g means foraccomplishing the clirm of the light produced by a dischargelllun'linating element Without reducing the electric potential of thepower supplied to the element and thus causing the element to flicker.

To illustrate my invention, I have shown on the tirawing, an electricaldischarge illuminating system comprising a plurality of elongated lurninescent elements 10, of type well known in the art and which are poweredfrom a suitable source of electrical energy 11 through switchingapparatus 13 and 8}tl5I1SfO1Hl8I 15, the ministry wimling l? of which isconnected through the switching apparatus to the source of power supply11. The secondary winding of the transformer 15 is or may be connectedas by the conductors 22 arge illumination i and 24 to spaced bus bars 21and 23. Itis between these bus bars that the several illuminatingelements are preferably connected in parallel circuits as shown,although, of course,

separate transformers, each powered in parallel from the power source11, may be employed to energize each circuit 25 separately. Obviouslyalso each circuit 25 may, if desired, contain one or severalilluminating elements 10 arranged in series, as is well known in the artand the circuits 25 also are preferably connected to the power buses 21and 23 through suitable switching and circuit; protecting apparatus 29.

In order to illustrate my invention, I have shown several banksor'circuits 25 extending bea tween the bus bars 21 and 23, each of thesecircuits includes one or more luminescent elements.

charge, without reducing or materially affectingthe discharge sustainingpotential applied to the iuminescent element. In order to illustrate myinvention, I have shown three modifications of the dimming means at 26,26' and 26, and it shouldbe understood that it is not essential toemploy a different modification of the dimming means in the differentcircuits but any. of the modifications shown may be used in all of thecircuits 25. As shown at 26, the means whichI prefer to employ inaccomplishing my purpose comprises, a transformer 28, the primarywinding 33 of which is connected by means of conclusters 37 and 39 witha means for varying the electrical characteristics of the primaryEircult of the transformer 28. lhe secondary 27 of this transformer isconnected in the circuit 25. In the embodiment illustrated at 26, themeans comprises a variable resistance and a condenser 41 is shuntedacross the opposite ends of the said resistance. Obviously other meansmay he employed to alter the characteristics or the are circuit 25 andto apply a variable reactive load therein, and it is within thecontemplation oi my invention, however, to employ any other' suitable orconvenient means for varying the electrical characteristics of theprimary circuit of the transioimer 28. I more especially contemplate theuse of a variable inductance, commonly called a variometer orvario-coupler in place of the variable resistance 35, aid variemeter tobe employed either with or' without the ccndenser 4L1. 1

it is thought that the secondary winding 27 of the transformer 28 actsas a reactance in'series with the luminescent element 10 for the reasonthat the core of the transformer becomes highly saturated and induces acurrent in the primary inwhich the power faction approaches zero. By varing the resistance in series in the primary of the transformer 28, thecurrent permitted tofiow in the primary may be regulated and adeterminate amount of reactive energy removed from the circuit 25without affecting the voltage ap plied to the tube. It the resistance inthe primary operate at maximum intensity On the contrary,

if the resistance is reduced to a minimum as by short-circuiting theprimary of the transformer. a maximum amount of reactive power will beabsorbed by-the transformer and its secondary circuit and the, tube willoperate at minimum intensity, i. e. will be dimmed. It is also possibleto employ the resista e without the condenser 41 in shunt therewith.also contemplate thepossibility of using other combinations of variablere- 'sistance or reactance, inductance and/or capacitance for thepurpose of varying the electrical characteristics of the second circuitof the transformer 28.

At 26' I have shown a modifled arrangement of the reactive dimmer meansin which the primary winding 33' of the transformer is connected, bymeans of the conductors 39', in series with one winding of thevario-coupler 41, the other winding of which is connected, by means ofthe conductors 37', in series with a resistor 35'. Under someconditions, it may be desirable to shunt a condenser across the primarywinding 33' of the transformer 28', the secondary 27 winding of which isconnected in series with the illuminating elements to be controlled.By'altering the inductive relationship of the coils of the variocoupler,as by relatively twisting them, the reactive characteristics of thedimmer device 26' are altered so that a variable reactive load isprovided for controlling the power supplied to the illuminatingelements.

At 26 I have shown still another mode of practicing my invention. Inthis embodiment, the primary and secondary windings of the transformer28"' are relatively shiftable so that this elementitself forms avario-coupler, the secondary winding 27 of which is connected in serieswith the illuminating elements, while the primary 33 is connected inseries with a resistor 35 by means of the conductors 37 and 39 Acondenser 4:1 also is shown in shunt relationship with the'resistor 35between the conductors 37 and 39 but it may be desirable, under certainconditions, to omit this condenser 41 By altering the inductiverelationship of the coils 27 and 33 as by relatively shifting them, thereactive load on the circuit 25 provided by the dimmer device 26 may bevaried in order to control the intensity of discharge illuminationcreated in the elements 10.

I have thus provided for the dimming of luminescent elements of thedischarge type without reducing the operating voltage and withoutcausing sputtering in the tube and I am able to produce any desiredintensity by varying the electrical characteristics of the transformer27, which in effect, creates a variable reactive load in series with thetube being regulated. This capable of producing an infinite variety ofinter-- mediate colors which will have particular value in theatricaland similar lighting.

It is thought that the invention and numerous of its attendantadvantages will be fully understood from the foregoing description andit will be understood that numerous changes may be madein the form,construction and arrangement of the several parts without departing fromthe,

spirit or scope of my invention or sacrificing any of its attendantadvantages.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is as follows:

1. An electric system comprising a series circuit including a dischargeilluminating element and one winding of a transformer, means to connectsaid series circuit to a source of electrical energy, the other windingof said transformer forming a portion of a variable circuit includingmeans to alter the electrical characteristics of the circuit whereby toconstitute the transformer as a variable reactive load capable ofabsorbing some of the power applied in said series circuit withoutchanging the voltage applied to the discharge illuminating element.

2. An electric system comprising a series circuit including a dischargeilluminating element and one winding of a transformer, means to connectsaid series circuit to a source of electrical power and avariablereactance connected in series with the other windings or" thetransformer.

3. An electric system comprising a series circuit including a dischargeilluminating element and one winding of a transformer,- means to connectsaid series circuit to a source of electrical power and a variable meansconnected to the other winding of said transformer for the purpose ofchangingthe reactive load created by the transformer in said seriescircuit.

l. An electric system comprising a discharge element, a power supplycircuit for said element;' a regulator circuit inductively coupled withthe supply circuit and reactive means in the roguelator circuit.

5. An electric system comprising a discharge element, a power supplycircuit for said element,

tor circuit, and means to vary the reactive characteristics of theregulator circuit.

6. An electric system comprising a discharge element, a power supplycircuit for said element, a regulator circuit inductively coupled withthe supply circuit and capacity reactance in the regulator circuit;

7. An electric system comprising a discharge element, a power supplycircuit for said element, a regulator circuit inductively coupled withthe supply circuit and a condenser in the regulator circuit. 7

8. An electric system comprising a discharge element, a power supplycircuit for said element, a regulator circuit inductively coupled withthe supply circuit and a condenser in the regulator circuit and means tochange the electrical characteristics of the regulatoncircult.

9. an electric system comprising a discharge element, a power supplycircuit for said element, a regulator circuit inductively coupled withthe I supply circuit, said regulator circuit comprising and means tovary the resistance in shunt with the condenser.

11. The method of controlling the intensity of illumination produced byan electrical discharge, which consists in inductively coupling acircuit, including a variable resistance and a shunted condenser, withthe power supply circuit from which the discharge is energized in theinductively coupled circuit.

12. An electric system comprising a discharge element, a power supplycircuit for said element, a regulator circuit inductively coupled withthe supply circuit and a variometer in the regulator circuit.

13. An electric system comprising a discharge element, a power supplycircuit for said element, a regulator circuit inductively coupled withthe supply circuit and a rheostat in the regulator circult.

it. An electric system comprising a discharge element, a power supplycircuit for said element, and a regulator circuit inductively coupledwith the supply circuit, said regulator circuit including a variableresistance.

15. In an electric system, a series circuit includ ing a dischargeelement, and one oi a transformer, means to energize saidserie'scircult, and a regulator circuit, for said series cir-= cuit,comprising, in series, another winding oi said transformer and means toproduce a variable inductive load in the series circuit for the purposeof controlling the intensity of illumination produced by the dischargeelement.

16. An electric system comprising a discharge element, a power supplycircuit for said element and a regulator circuit inductively coupledwith the supply circuit, said regulator circuit including reactive meansand a variable resistance.

17. An electric system comprising a discharge element, a power supplycircuit for said element, 11 a regulator circuit inductively coupledwith the supply circuit and means to vary the reactance oi the regulatorcircuit.

18. An electric system comprising a discharge element, a power circuitfor said element, reactive means inductively associated with the pow ersupply circuit and means to vary the reactive characteristics or thereactive means whereby to control the intensity of illumination producedby the discharge element.

19. An electric system comprising a plurality of controllableilluminating hanks comprising discharge means, said hanks beingconnected for parallel operation from a common power source and eachhank including a discharge element, a power circuit for said element,reactive means inductively associated with the power supply circult andmeans to vary the reactive characteristics of the reactive means wherebyto control the intensity of illumination produced by the discharge meansof the hank independently oi the other banks.

20. The method of controlling the intensity of illumination produced byan electrical discharge, which, consists in inductively coupling acircuit, including a variable reactance, with the power supply circuitfrom which the discharge is energized in the'inductively coupledcircuit.

. ROBERT E. BARCLAY.

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